1. Field of the Invention
This invention relates to a vertically adjustable lamp of the type having a light attached to one end of a lamp bar, movement of the lamp bar and support by an adjustment bar providing desired vertical position for the light. In the adjustable lamp of the present invention, the lamp bar pivots relative to a base at the end opposite to the light providing generally vertical pivotal movement of the lamp bar and a support means is provided supporting the lamp bar at a support point between the pivot end and the end carrying the light to provide desired vertical positioning of the lamp.
2. Description of the Prior Art
A wide variety of adjustable lamps are known which provide a light fixture at the end of a bar-type structure. A large number of such lamps have the pivot point in a central position on the bar structure so as to provide a counterpoise effect as illustrated by U.S. Pat. No. 3,413,459 and in Catalogue Recapitulatif, Stilnovo, Milano, Italy, April 1984, particularly at page 3, Catalog No. 32022, 32012, 12011/2/3. A double counterbalanced arm system is taught by U.S. Pat. No. 3,409,767. It is also known to provide "gooseneck" lamp arms which are constructed of flexible material and may be bent to retain their shape at the desired positioning. Lamp arms which are rotatable about a pivot point and require adjustment of the pivot position by loosening or tightening the pivot mechanism are also known to the art.
Phillips, U.S. Pat. No. 2,740,039 teaches a vertically and angularly adjustable lamp of the electric portable desk type for use in offices and the like. The lamp supporting structure has a base and a separate and distinct vertically disposed rotatable post. The rotatable post is mounted on the base. A tubular bearing is pivotally mounted at the top of the post and an elongated supporting arm is slidably carried by the pivotally mounted bearing. The supporting arm has a lamp affixed at one end of the supporting arm. The supporting arm has transverse grooves which mate with a pin and allow the supporting arm to slide along its longitudinal axis with respect to the pivotally mounted bearing.
Denecke, U.S. Pat. No. 1,781,372 teaches a light support having a base, an upright, an extension arm, and a light suspended from the outer end of the arm. Terry et al., U.S. Pat. No. 4,314,319 teaches an adjustable lamp having a main arm pivotally attached to a base at one end and carrying a lamp housing at the other end. A spring urged link having adjustable frictional resistance to sliding is connected to the main arm at an upper end and to the base at the opposite end of the main arm.